<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<title>web</title>
		<script type="text/javascript">
// 			var n1=123;
// 			n1++;
// 			++n1;
// 			alert(n1);
			var n1=123;
			// var n2=n1++;
			var n2=++n1;
			alert(n1);
			alert(n2);
		</script>
	</head>
	<body>
		
	</body>
</html>